Grounded theory is a research methodology that builds theory from data rather than starting with a hypothesis and testing it. Developed in the 1960s as a challenge to the dominant assumption that rigorous research had to follow a deductive, numbers-driven model, it offers a systematic way to collect and analyze qualitative data and arrive at a theoretical explanation that is “grounded” in what participants actually said, did, or experienced. The approach has since spread well beyond its origins in sociology, generating ongoing debates about how strictly to follow its original rules and what counts as doing it well.
Where Grounded Theory Came From and Why It Mattered
Grounded theory emerged from a collaboration between two sociologists, Barney Glaser and Anselm Strauss, who were studying how terminally ill patients dealt with the knowledge that they were dying and how healthcare staff responded. During that research, they questioned whether the standard scientific method of starting with a theory and then verifying it was the right fit for understanding something so deeply human. They developed what they called the constant comparative method, a technique for continuously comparing new data against data already collected and emerging ideas. Their observations on dying eventually became the book Awareness of Dying (1965), and their methodological argument was published in The Discovery of Grounded Theory (1967), which laid out how theory could be generated inductively from data rather than imposed from the top down.
The timing mattered. In the 1960s, quantitative methods dominated the social sciences, and qualitative research was often dismissed as anecdotal or unscientific. Glaser and Strauss offered a structured, replicable process that gave qualitative work methodological credibility. Their framework challenged the idea that quantitative methodology was the only valid way to determine truths about the world.1PubMed Central. Grounded theory research: A design framework for novice researchers That argument opened the door for generations of researchers in nursing, education, management, psychology, and dozens of other fields to use qualitative data as the foundation for theory rather than merely as illustration.
How the Process Works
Grounded theory is not a single technique but a coordinated set of practices that cycle back and forth between collecting data and analyzing it. Unlike methods where you gather all your data first and then sit down to figure out what it means, grounded theory insists that collection and analysis happen simultaneously. You interview someone, you analyze what they said, and what you find shapes who you talk to next and what you ask them. This iterative loop is one of the methodology’s defining features.
The process rests on a few core activities: coding, memo writing, theoretical sampling, and the pursuit of saturation.
Coding in Stages
Coding is the engine of grounded theory analysis. It means labeling segments of your data with short descriptive or conceptual tags. But it does not happen all at once. In the version of grounded theory that evolved from Strauss’s later work, coding moves through three phases. Open coding is where you break data apart and develop initial categories. Axial coding is where you start connecting those categories to each other, identifying relationships and sub-categories. Selective coding is where you identify a core storyline that ties the categories together into a coherent set of theoretical ideas.2PubMed Central. Grounded theory research: A design framework for novice researchers – Section: Coding Each stage moves the analysis from concrete description toward abstract theory. The terminology shifts slightly depending on which version of grounded theory you follow, but the general movement from fragmented observations to integrated explanation is consistent across all of them.
Memo Writing
If coding is the engine, memo writing is the steering. Memos are the researcher’s running written record of their analytical thinking: hunches, comparisons between categories, questions about what a piece of data means, speculations about how two ideas connect. They can be brief and rough early on and become more elaborate as the study progresses. Writing memos is the process through which a researcher transforms raw data into theory, analytically interpreting the data, discovering emergent patterns, and gradually increasing the level of abstraction.3The SAGE Handbook of Grounded Theory. Asking Questions of the Data: Memo Writing in the Grounded Theory Tradition The practice allows a researcher to move from description to richer, more conceptual thinking, ultimately building toward a sophisticated theoretical model.4European Journal of Humanities and Social Sciences. Writing Memos: A Vital Classic Grounded Theory Task
Memo writing is not optional or decorative. It is the methodological link between data and theory. Researchers who skip or shortchange memos often end up with findings that stay descriptive, cataloguing themes in the data without ever building an explanatory framework around them. One of the most common criticisms of published grounded theory studies is that they present a list of themes rather than a theory, and inadequate memo work is usually why.
Theoretical Sampling and Saturation
In most research, you decide in advance who you will study and how many participants you need. Grounded theory works differently. Theoretical sampling means that you let your emerging analysis guide your next data collection decisions. If your early interviews suggest that a particular experience or condition is important to the developing theory, you deliberately seek out participants who can shed light on that experience. You keep sampling until the categories are fully developed and no new information is emerging that changes them. Theoretical sampling and theoretical saturation are inseparable: sampling continues until all the structures of the phenomenon, such as themes, categories, and relationships, are fully identified and the emerging theory is complete.5International Journal of Nursing Studies Advances. Saturation in qualitative research: An evolutionary concept analysis – Section: Theoretical saturation
In practice, saturation is one of the trickiest concepts in grounded theory. There is no formula for declaring it. Researchers have to make a judgment call, and reviewers sometimes question whether saturation was genuinely reached or whether the researcher simply ran out of time or funding. The concept is widely invoked but inconsistently applied, and debates about what saturation actually means and how to document it have been going on for decades.
Three Major Schools of Thought
Glaser and Strauss eventually parted ways, and their disagreements produced distinct versions of grounded theory that researchers still argue about. A third major variant arrived later. The three main approaches are classic Glaserian grounded theory, Straussian grounded theory, and constructivist grounded theory.6PubMed Central. Discriminating among grounded theory approaches
Glaserian grounded theory stays closest to the original 1967 framework. It emphasizes emergence: the researcher should approach the data with as few preconceptions as possible and let the theory emerge from what is there. Coding is less structured, and the researcher avoids forcing data into predetermined categories. Strauss, working later with Juliet Corbin, developed a more systematic and prescriptive version. Straussian grounded theory introduces more formal coding procedures and allows for a greater role of verification during analysis. The differences between these two approaches have created genuine confusion, particularly for newer researchers trying to figure out which set of procedures to follow.7Journal of Management Inquiry. Grounded Theory in Practice: Novice Researchers’ Choice Between Straussian and Glaserian The root of the disagreement is partly philosophical: Glaser believes that excessive procedural structure forces data into the researcher’s framework rather than allowing patterns to surface naturally, while the Straussian approach argues that some structure helps researchers stay rigorous rather than vague.8PubMed. Developing a grounded theory approach: a comparison of Glaser and Strauss
The third variant, constructivist grounded theory, was developed by Kathy Charmaz beginning in the 2000s. Charmaz took an interpretivist stance, arguing that reality is socially constructed and that meaning is co-created between the researcher and participants. This stands in contrast to the classic version, where the researcher is positioned as an objective observer. Constructivist grounded theory embraces the researcher’s existing knowledge as useful for identifying data that have value to theory generation.9PubMed Central. A Practical Example of How to Apply Constructivist Grounded Theory Methodology: Exploring Patient Experiences During Paramedic Led Healthcare It also places greater emphasis on the researcher’s reflexivity and the social conditions that shape both the data and its interpretation. For researchers studying topics where power, identity, and context matter heavily, this version often feels like a better fit.
The Literature Review Debate
One of the most enduring controversies in grounded theory circles is when, if ever, a researcher should read the existing literature on their topic. The original recommendation from Glaser was clear: delay the literature review until after your theory has emerged, so that you approach the data with an open mind rather than having your analysis colored by what others have already found. The logic is intuitive. If you have already read ten studies arguing that X causes Y, you are more likely to see X-causes-Y patterns in your own data whether they are truly there or not.
But this advice has come under increasing pressure. For one thing, most researchers do not enter a study as blank slates. They choose their topic because they already know something about it and find it interesting. Ethics review boards often require a literature review before granting approval. Funding bodies expect applicants to demonstrate knowledge of the field. And mounting evidence suggests that a preliminary review can actually enhance the researcher’s theoretical sensitivity and rigor, potentially leading to more innovative insights rather than less.10PubMed. The timing of the literature review in grounded theory research: an open mind versus an empty head The distinction some researchers draw is between having an open mind and having an empty head. You can be knowledgeable about a topic and still remain genuinely open to what the data show, as long as you are reflexive about your assumptions.11PubMed. Grounded theory research: literature reviewing and reflexivity
In practice, how you handle the literature review depends partly on which school of grounded theory you follow. Classic Glaserian researchers still tend to delay it. Straussian and constructivist researchers are more comfortable with an early review, especially if it serves the practical function of sensitizing the researcher to relevant concepts without dictating what they should find.
Reflexivity and the Researcher’s Position
Constructivist grounded theory, in particular, has pushed the field toward taking reflexivity seriously. Reflexivity means examining how your own identity, assumptions, values, and relationship with participants shape the research process and its outcomes. It is not just a philosophical nicety. Researchers who fail to interrogate their own position risk mistaking their assumptions for findings.
Constructivist grounded theory enables researchers to confront the multiple ways in which deeply embedded aspects of identity, personal values, biases, and emergent research relationships affect the research process.12South African Journal of Higher Education. Labyrinth moments: Evidencing reflexivity in intersectional research using constructivist grounded theory This is especially relevant when research crosses cultural boundaries. A researcher studying the experiences of refugees, for example, brings their own cultural lens to the interpretation of interview data, and being transparent about that lens is part of producing trustworthy theory. Memo writing serves double duty here: beyond tracking analytical development, memos become a space for documenting the researcher’s evolving awareness of their own biases and how those biases might be shaping what they see in the data.
Induction, Abduction, and the Limits of Emergence
Grounded theory is routinely described as an inductive method, and at a basic level that description holds: you move from specific observations in the data toward general theoretical statements. But a long-standing philosophical critique points out that pure induction, just stacking up observations, does not by itself produce creative theoretical insights. You can notice patterns all day without ever arriving at an explanation for why those patterns exist.
Some scholars have argued that what grounded theory researchers actually do when they produce good theory is not pure induction but something closer to abduction, a form of reasoning identified by the philosopher Charles S. Peirce. Abduction involves generating the best possible explanation for a surprising or puzzling observation. It is a creative leap, not a mechanical one, and it is more consistent with how theoretical breakthroughs actually happen in practice. This critique suggests that grounded theory’s commitment to letting theories “emerge” from data, while useful as a guard against premature theorizing, understates the active, creative role the researcher plays in constructing an explanation.13Sociological Theory. Theory Construction in Qualitative Research The implication is practical: researchers who sit passively and wait for the data to tell them what it means may end up with descriptions rather than theories. The best grounded theory work involves active interpretive effort, not just careful coding.
Where Grounded Theory Gets Used
Although grounded theory was born in sociology, it spread rapidly into other fields. Nursing adopted it early and has been one of its most prolific users since the 1970s.14PubMed Central. Application of classic grounded theory in nursing studies: a qualitative systematic review protocol This makes sense: nursing research often deals with patient experiences, care relationships, and clinical processes that are not well served by purely quantitative approaches. Questions like “how do patients manage chronic pain at home” or “what happens in the relationship between a nurse and a dying patient” are exactly the kind of questions grounded theory was designed to address.
Management and organizational studies also use grounded theory extensively, though the application has sometimes been uneven. Studies in this field have explored topics like organizational change, leadership behavior, and decision-making under uncertainty. One challenge is that researchers in management sometimes pick up grounded theory’s language, using terms like “theoretical sampling” and “constant comparison,” without fully following the methodology’s procedures, which dilutes the quality of the resulting work.15Organizational Research Methods. Pragmatic Reflections on a Conversation About Grounded Theory in Management and Organization Studies Education, psychology, information science, and public health have also adopted the approach. Wherever researchers are trying to understand complex human experiences from the perspective of the people living them, grounded theory tends to show up.
Assessing Quality and Rigor
A recurring question in grounded theory research is how to tell a good study from a weak one. Because the methodology is flexible and interpretive, the usual markers of scientific quality, like statistical significance or replication, do not apply. Instead, rigor in grounded theory is assessed through criteria like whether the researcher stayed true to the data without manipulating it, whether the constant comparative method was genuinely applied throughout, and whether the resulting concepts are truly conceptual rather than just descriptive labels for data clusters.16Grounded Theory Review. Procedural and Methodological Rigor in Classic Grounded Theory
One practical test readers and reviewers can apply: does the study produce a theory, or does it produce a list of themes? A genuine grounded theory explains a process, relationship, or pattern. It tells you how something works, not just what is there. Many published studies that claim to use grounded theory end up presenting thematic analyses with grounded theory vocabulary sprinkled on top. The distinction matters because the entire point of the methodology is theory generation. Without that, you have borrowed the label without completing the work.
Software Tools and the AI Frontier
Grounded theory was originally done with paper, scissors, and index cards. Researchers literally cut up transcripts and sorted the pieces into piles. The arrival of computer-assisted qualitative data analysis software changed the logistics considerably. Programs designed for qualitative analysis facilitate the iterative process of moving between data collection and analysis, coding, writing memos, and creating models.17Field Methods. Using Computer-Assisted Qualitative Data Analysis Software to Develop a Grounded Theory Project These tools do not do the analytical thinking for you, but they make it much easier to manage large volumes of data, search across codes, and reorganize your emerging framework as it develops.
More recently, large language models have entered the picture. Early experiments have attempted to automate parts of the grounded theory process, including coding qualitative data, developing themes, and building preliminary theoretical models. One prototype system, AcademiaOS, used language models to process interview transcripts and develop grounded theoretical models, and a small user study of 19 academics found some acceptance of the system’s potential to assist with qualitative research.18arXiv. AcademiaOS: Automating Grounded Theory Development in Qualitative Research with Large Language Models The results are preliminary, and the implications are contentious. Grounded theory was designed to keep the researcher deeply immersed in the data, and outsourcing coding to a language model raises real questions about whether the resulting analysis is genuinely “grounded” in the researcher’s engagement with participants’ meanings. Still, the technology is developing fast, and its role in qualitative research is likely to grow whether purists welcome it or not.
Mixing Grounded Theory With Other Methods
Grounded theory is increasingly being combined with other research approaches rather than used in isolation. Mixed methods designs that pair grounded theory with quantitative data collection have become a recognized area of methodological development. One proposed framework involves using grounded theory to build a theoretical model from qualitative data, then testing that model quantitatively, and finally integrating the results into a refined theory.19Journal of Mixed Methods Research. A Mixed Methods–Grounded Theory Design for Producing More Refined Theoretical Models The appeal is clear: grounded theory generates explanations, and quantitative methods can check whether those explanations hold up in larger, more representative samples.
Not everyone agrees this combination works smoothly. The philosophical underpinnings of grounded theory, especially the constructivist version, sit uncomfortably with the assumptions of many quantitative methods. If you believe that meaning is co-constructed between researcher and participant, it is a strange move to then hand a resulting model to a survey study that treats respondents as interchangeable data points. Pragmatically minded researchers tend to shrug off these tensions and focus on what produces useful knowledge, but the philosophical disagreements are real and worth being aware of if you are evaluating a mixed methods grounded theory study.
Teaching Grounded Theory
Learning grounded theory from a textbook is notoriously difficult. The methodology requires a tolerance for ambiguity that most graduate students have not been trained for, and the iterative, nonlinear process feels disorienting to people accustomed to following a step-by-step protocol. Effective grounded theory pedagogy tends to rely on demonstration, collective participation, progressively complex tasks, and a supportive environment where students feel safe making analytical mistakes.20PubMed. Teaching Theory Construction With Initial Grounded Theory Tools: A Reflection on Lessons and Learning
One challenge in the classroom is the sheer number of competing versions. Students who read Glaser, then Strauss and Corbin, then Charmaz may come away more confused than when they started, because each source uses slightly different terminology, offers different procedural guidance, and holds different philosophical assumptions. A common piece of advice for newcomers is to pick one approach, learn it thoroughly, and apply it consistently within a single study, rather than blending elements from different schools without understanding the reasoning behind each. That kind of methodological mixing, however well-intentioned, is one of the main drivers of weak grounded theory research. The tools look similar across versions, but the logic connecting them is different, and borrowing a tool from one school while following the logic of another produces studies that satisfy none of the approaches fully.